"We're both a little less timid around each other," Matt said in an interview with USA Today last year. "Some of these teams that are newish, they kind of have that honeymoon phase where they don't want to yell at their partner or criticize or anything, walking on eggshells ... We're way past that."

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Alex and Maia Shibutani — the "Shib Sibs" — are an ice dancing duo for the US.

Maia Shibutani, left, and older brother Alex.
Ben Margot/AP

"We stand out," Alex said in a recent interview on the "Today" show. "We're the only sibling team that's going to be competing at the Olympic Games and so we bring something different to the table."

The Shibutanis made their Olympic debut at the 2014 Sochi Games, where they placed ninth, according to Team USA.

Cross-country skiers Caitlin Patterson and younger brother Scott will make their Olympic debut in Pyeongchang.

Alaska-born Logan and Reese Hanneman are the third sibling pair on the US cross-country team.

"We have been competing against each other, in one sport or another, for our entire lives, and the brotherly competition and cooperation has undoubtedly propelled us to this point," Reese, the older of the two brothers, said in an interview with Alaska newspaper The Daily News-Miner.

Canadian brothers Christian and Scott Gow are competing in the biathlon at their first Olympic Games.

Christian Gow, left, and older brother Scott.
Stanko Gruden/Getty

Biathlon combines long-distance cross-country skiing and rifle shooting. That's not a random pairing: the sport is based on survival skills used by hunters in snowy Scandinavian forests, according to the IOC.

Charles and François Hamelin are Canadian speed skaters with a long Olympic history.

The brothers have won a combined five medals (four gold, one silver) over the years. Pyeongchang marks their third time competing at the Olympics.

"Two happy faces that were going to their first Olympic games 8 years ago," François, the younger of the two, captioned an Instagram photo of the brothers posted January 31. "Those same two faces are taking off tomorrow for their third games together."

British skiers Katie and Molly Summerhayes will compete in slopestyle.

In slopestyle, athletes ski through courses filled with jumps, rails, and half-pipes, performing a series of gravity-defying tricks. It's an intense sport, but the Summerhayes sisters are intense athletes with a spark of sibling rivalry: The pair told Team GB that they still race each other up flights of stairs.

Italy's Manuela and Manfred Moelgg will compete in alpine skiing.

Even though Manfred is the older sibling, he still looks up to his sister. "Manuela is also a role model for me," he said in a 2012 interview for the International Ski Federation. "We grew up skiing together ... We have always pushed and motivated each other."